Calculating machine



March 6, 1934. c, M, FRIDEN 1,949,741

CALCULAT ING MACHINE Filed June 2a, 1928 a Sheet-Sheet 1 1 INVENTORCarj/ M E Fr'lden WWW & A TTORNEYS I March 6, 1934.

C. M. F. FRIDEN CALCULATING MACHINE Filed June 23, 1928 8 Sheets-Sheet 2FIE E F15 CE IN VEN TOR Car-f M- E FP/a'err A T'I'ORNEYS 8 Sheets-Sheet3 A TTORNEYS w WW LE w I c X? Q Q 7 1| 0 mmh March 6, 1934. c. M F.FRlDEN CALCULATING MACHINE Filed June 23, 1928 March 6, 1934. c. M. F.FRIDEN CALCULATING MACHINE Filed June 23, 1928 8 Sheets-Sheet 4 INVENTOR By Car M. E Friden ATTORNEYS March 6, 1934.

c. M. F. FRIDEN CALCULATING MACHINE Filed June 23, 1928 8 Sheets-Sheet 5Hide/1 WA/Mg mm Car/ INVENTOR M BY A TTORNE YS Match 6, 1934.

v c. M. F. FRIDEN CALCULATING MACHINE 8 Sheets-Sheet 6 Filed June 25,1928 F1 F5 E Fi -5]; FlE l|:1

INVENTOR Carl M- E fiv'den Mfdfj A TTORNE YS March 6, 1934. c M F F EN1,949,741

CALCULATING MACHINE Filed June 23, 1928 8 Sheets-Sheet 7 FIE- ll- IN VENTOR Y Carl F Figs/1 M 221 ATTORNEYS March 6, 1934. c. M. F. FRIDEN 9,

CALCULATING MACHINE Filed June 25, 1928 8 Sheets-Sheet 8 INVENTOR CarM.F: Fmderr Wwiz/ A TTOR NE YS Patented Mar. 6, 1934 UNITED STATESPATENT OFFICE,

Marchant Calculating Machine Company,

Emeryville, Calif., a corporation of California Application June 23,1928, Serial No. 287,679

12 Claims.

The invention relates to calculating machines for use in performingproblems in addition, subtraction, multiplication and division.

An object of the invention is to provide a small and compact, handoperated. calculating machine capable of performing problems in the fourcardinal calculations. 1

Another object of the invention is to provide a calculating machine of asimple and sturdy construction, to permit quantity production at lowcost, while maintaining the accuracy necessary in a successfulcalculating machine.

Another object of the invention is to provide a calculating machine ofthe keyboard type, provided with improved means for controlling thelocking and the release of the depressed keys.

Another object of the invention is to provide an improved actuatorconstruction, in which the product register actuator and the multiplierregister actuator are coaxial and, further, to provide means forreversing the relative directions of rotation of the two actuators.

A further object of the invention is to provide an improved form of zeroresetting mechanism for the product and multiplier register.

The invention possesses other advantageous features some of which, withthe foregoing, will be set forth at length in the following description,Where I shall outline in full that form of the invention which I haveselected for illustration in the drawings accompanying and forming partof the present specification. In said drawings I have shown one form ofcalculating machine embodying my invention, but it is to be understoodthat I do not limit myself to such form, since the invention, as setforth in the claims, may be embodied in a plurality of forms.

Referring to said drawings, Figure 1 is a side elevation of 'acalculating machine embodying means for shifting the carriage and themeans for reversing the direction of rotation of one actuator withrespect to the other.

Figure 3 is a section taken through the axis of the shaft of theactuator reversing mechanism.

Figure 4 is a vertical longitudinal section through the calculatingmachine showing the means for controllingthe locking and the release ofthe depressed keys.

Figure 5 is a vertical longitudinal section through the machine showingthe means for locking the selecting elements of the actuator in setposition and for controlling the locking means.

Figure 6 is a vertical longitudinal section through the calculatingmachine showing a row of value keys and the means for transferring thevalue represented by the depressed keys to the 0 associated selectingelement of the actuator.

Figure '7 is a perspective view of the locking bar for locking thedepressed key holding latches. Figure 8 is a part elevation, partvertical section, of the two part actuator, one actuator part comprisingthe ordinal registration members and the tens carryingniembers forcooperation with the product register, and the other actuator partcomprising the tens carrying members and the ordinal registrationmembers which cooperate Figure 13 is a section taken on the line 13-13,8

Figure I1.

Figure 14 is a section taken on the line 14-44, Figure 11. Figure 15 isa detail of the driven member of the selecting clutch which operates thezero re- 9 setting mechanism.

Figure 16 is a side elevation, Figure 17 is a front elevation, andFigure 18 is an opposite side elevation, of the driving member of thezero resetting mechanism clutch.

Figure 19 is an elevation of the carriage shifting mechanism.

Figure 20 is a plan view of the carriage shifting mechanism and themeans for positioning the carriage in its proper relation to theoperating units of the actuator.

The calculating machine shown in the drawings is of the reversible cycletype and includes an actuator which is rotatable in either directionfrom full cycle position, to assist calculation.

The machine comprises two actuators, a product m register actuator, anda multiplier register or quotient register actuator. The productregister actuator includes ordinal registration members which cooperatewith the numeral wheels of the product register, and selecting elements,which merical orders.

are selectively adjustable to determine the extent of the operation ofthe ordinal registration member on the numeral wheels of the productregister.

The product register actuator is also provided with tens carryingmembers. The multiplier or quotient register actuator comprises a singletooth ordinal registration member and tens carrying members. The numeralwheels of the product register and the numeral wheels of the multiplieror quotient register are arranged on a carriage which is movabletransversely on the calculating machine to permit direct action of theactuators upon the numeral wheels of different nu- The actuator isrotated by a hand crank, which is rotatable in either direction fromfull cycle position. The calculating machine comprises a suitable frame,including the side plates 2 and 3, between which, and on which, thevarious devices entering into the construction of the entire machine,are mounted. The machine includes a product register actuator comprisinga plurality of selecting elements, ordinal registration members, andtens carrying members. The selecting elements and ordinal registrationmembers are constructed in accordance with the disclosure in my UnitedStates Patent No. 1,524,924, issued February 3rd, 1925. The productregister actuator is mounted on a shaft 5, which is journalled in theside plates 2 and 3, the ordinal registration members being secured tothe shaft to rotate therewith, and the selecting elements beingrotatably mounted on the shaft so that they may be positioned withrespect to the shaft and so that they may be held stationary duringrotation of the shaft.

The tens carrying members, or pins 6, are carried by the ordinalregistration members. Each selecting element, '7, which is provided witha cam 8, which controls the projection and retraction of the actuatingslide of the ordinal registration member, is provided with a gear 9,which meshes with a curved rack 12 formed on the end of the lever 13,fulcrumed on the shaft 14, there being one lever 13 for each selectingelement '7.

Values are introduced into the actuator by moving the selecting elements'7 to selected positions and in the present construction, this isaccomplished by the depression of keys which are associated with anddetermine the movement of the lever 13 and, consequently, the movementof the selecting element '7. Associated with each selecting element is arow of value keys, comprising nine keys, numbered from one to nine,consecutively, and a clearance or zero key. The clearance key 16 isusually rranged at the front of the row, behind which the numeral keys17 are disposed in consecutive order. Below the stems 18 of the keys1'7, and in cooperation with the stems, is a duplex lever 21, 22, whichis connected at its rear end with the lever 13. The lever 21 isfulcrumed on the bracket 23 and the lever 22 is fulcrumed on the bracket24, and the two levers are connected intermediate their ends by the slotand pin 25. Depression of any key 17 rocks the lever 22 a distancecorresponding to the value of ment of the slide, against the pressure ofthe spring 29, will cause the release of the depressed key 17. Theclearance key 16 is provided with a longer cam member 31, which willcause backward movement of the slide 26, but which will not engage underthe slide. The spring 29 is disposed between the key frame 32 and theturned up lip 33 on the front end of the slide 26. Means are providedfor locking the slides 26 against releasing movement during the timethat the actuator is out of full cycle position and other means areemployed for moving the slide during the rotation of the actuator, forthe purpose of releasing the depressed keys, and these means will behereinafter described.

For the purpose of convenience in construction, the actuator shaft isformed in two parts, 5 and 5A, the part 5A constituting an extension ofthe part 5. To accomplish the connection of the two shafts, the shaft 5is provided on one end with a socket 34, into which the end of the shaftpart 5A extends, this shaft being provided with a slot to receive a pin35 whereby the two shaft parts are rotatably secured together.

Mounted on the shaft part 5A, by the roller bearings 36, is a hollowshaft 37, to which are secured the tens carrying units 38 of themultiplier register actuator and the single toothed ordinal registrationmember 39 of the multiplier register actuator.

The actuators are rotated by a hand crank 42, which is provided with agear 43 meshing with the gear 44, which in turn meshes with the gear 45,secured to the shaft 5A. The crank 42 is rotatable in either directionfrom full cycle position to rotate the shaft 5A in either direction.

Means are provided for causing the shaft 5A and 37 to rotate in the sameor in opposite direction. In performing calculations in division, thetwo shafts rotate in the same direction, whereas in performingcalculations in multiplication, the two shafts rotate in oppositedirections. Secured to the hollow shaft 37, adjacent the gear 45, is agear 46 of the same tooth pitch. J ournalled on a stub shaft 47, mountedin the side plate 3, is a gear 48 (Fig. 3) which is in mesh with thegear 45. Mounted on the stub shaft 4'7 is a rocking arm 49 carrying agear 51, meshing with the gear 48, and adapted, on the rocking of thearm 49, to move into and out of engagement with the gear 46. Mounted onthe arm 49 on the other side of the fulcrum from the gear 51, is a gear52 which is of sufficient Width to simultaneously engage both gears and46. Means are provided for rocking the arm 49 to bring the gear 52 intomesh with the gears 45 and 46, at which time the gear 51 is out ofengagement with the gear 46, or to bring the gear 51 into engagementwith the gear 46, at which time the gear 52 is out of engagement withthe gears 45 and 46. When the gear 52 is in engagement with the gears 45and 46, it is evident that the shafts 5 and 37 will rotate in the samedirection and when the gear 51 is in engagement with the gear 46, it isevident that the shafts 5 and 3'7 will rotate in opposite directions.

The rocking arm 49 is rocked to set position by the keys 54 and 55,designated respectively, the multiplier key and the division key; thestems of these keys are provided with shoulders and extend through slotsin the top plate 56 of the keyboard and the stems are pivoted at theirlower ends to the rocking lever 57, which is connected by the link 58 tothe rocking arm 49. The key stems are urged toward the side on which theshoulders occur by the springs 61 and 62, so that when one key isdepressed, the shoulder of the other key overlies the top plate 56,holding the locking lever 57 in set position. Means are provided forpreventing the rocking lever 57 from coming to rest in said centerposition, this means comprising a compression spring 63, which serves tothrow the rocking lever to either of its ex-= treme positions, as itpasses through said center. When the machine is to be employed insolving problems in division, the key 55 is depressed and when themachine is to be used in solving problems in multiplication, the key 54is depressed, the depression of these keys serving to actuate thereversing mechanism interposed between the product register actuator andthe multiplier or quotient register actuator.

On rotation of the product register actuator, the values entered thereinare transferred to the numeral wheels of the product register and, themultiplier or quotient register is actuated by the single toothedactuating element39 and the tens carrying members 38. The numeral wheelscomprising the product register and the multiplier or quotient register,are mounted in a carriage which is movable transversely of thecalculating'machine to permit direct action of the actuators upon thenumeral wheels of different numerical order. The carriage 65 is arrangedabove and behind the actuators and is provided with a rear plate 66,upon which the registers are mounted and which is slidable in guideways,so that the carriage may readily be shifted. Secured to the back of andspaced from the rear plate 66 is a horizontal rack 67', which is engagedby a pinion 68. The pinion is connected through the gears 69, 71 and 72,with the shaft 73 which extends to the front of the machine, where it isprovided with a hand wheel '74. Rotation of the hand wheel causestransverse movement of the carriage.

The carriage is also provided with means for positioning it in properspace position with respect to the actuator units. For this purpose, theplate 66 is provided on its rear surface with a serrated plate 75, theserrations being engaged by a roller '76, carried by the spring pressedlever 77. Therroller serves to hold the carriage in set position, toproperly position the carriage and to emphasize the step-by-step spacingof the operating positions of the carriage.

The product register comprises a series of numeral wheels 81 and themultiplier or quotient register comprises a series of numeral wheels 82,the numeral wheels of bothregisters being independently rotatablymounted on the shaft 83. Each numeral wheel is provided on one side witha gear 8% which is in mesh with an intermediate gear 85, which lattergear is engaged by the ordinal registration members and the tenscarrying members of the actuators, on rotation of the actuators. Theusual tens carrying levers or transfer levers 86 are associated witheach intermediate gear 85.

The numeral wheels 81 and 82 are held against free rotation by thespring pressed detent 87, there being one detent associated with eachgear 84. The detents are held in engagement with the gear wheels 84 byspring pressed balls 96, the balls associated with the detents of theproduct register being seated in the rock shaft '88 and the balls 90associated with the detents of the multiplier or quotient register beingseated in-the rock shaft 89, the two rockshafts being in aline-' mentand being separately rockable.

Means are provided for independently resetting the registers to zero.Each numeral wheel 81 and 82 is provided with an inwardly extendingtooth 91, spaced slightly from the shaft 83. Seated in the shaft, andpartially extending therefrom is a plurality of spring pressed balls 92,there being one ball associated with each numeral wheel. The ballsextend outward sufiiciently to engage the teeth 91 and the springsbehind the balls are of such strength, that when the numeral wheel isrotated by the ordinal registration member or by the tens carryingmember, that the tooth 91 may pass, over the balls by causingcompression of these springs. Likewise, when the numeral wheels arerestrained against rotation by the detents 87, the balls 92 will pass bythe teeth 91 without causing rotation of the numeral wheel. Means areprovided for releasing the detents associated with the respectiveregisters, when it is desired to reset the registers to zero, and thesereleasing means are selectively operable so that operation of the zeroresetting operating device in one direction will cause the numeralwheels of one register to be reset to zero, and rotation of the zeroresetting operating device in the opposite direction will cause thenumeral wheels of the other register to be reset to zero. If the detentsassociated with the numeral wheels 81 are released, rotation of theshaft 83 will return the numeral wheels 81 to zero position, withoutmoving the numeral wheels 82, and, if the detents associated with thenumeral wheels 82 are released, rotation of the shaft 83 will return thenumeral wheels 82 to zero position, without rotating the numeralwheels81. The numeral wheels of the two reg- .lh isters are reset to zero bythe hand crank 93 and, means are provided whereby rotation of the handcrank in one direction, will release the detents associated with thenumeral wheels of one reg-= ister, to permit the numeral wheels to bereturned 115 to zero, and rotation of the hand crank in the oppositedirection, will release the detents associated with the other register,to permit the other register to be returned to zero. All of the numeralwheels are mounted on the same shaft and rotation of the shaft in onedirection returns the numeral wheels of one register to zero androtation of the shaft in the other direction returns the numeral wheelsof the other register to zero. The numeral wheels are stopped in zeroposition, when they are being reset to zero by the operation of thecrank 93, by contact of a single toothed element 94, secured to eachnumeral wheel with the rear end of the transfer or tens carrying lever86. This construction is well known in the art and .1321) requires nofurther description here, since numer a1 wheels in many calculatingmachines, are stopped in zero positions, by the transfer lever.

The hand crank 98 is secured to the shaft 83 on which the numeral wheelsof both registers are mounted. Secured to the shaft 83, adjacent one endthereof, is a collar 95 which abuts a sleeve 96 which is rotatable withrespect to the shaft 83. Secured to the sleeve 96, and lying adjacent tocollar 95, is a disc 97, shown in detail in Figure 15, which disc isprovided with two cutout portions 98 and 99, of different lengths, theportion 98 being shorter than the portion 99. Splined to the collar 95,and associated with the disc 97, is a clutch washer 192, shown in detailin Figures 16, 1'7 and 18. The clutch washer is pressed against the disc9'7 by the spring 103. The clutch washer is provided with a tooth 104which normally engages in the short cutout portion 98 of the disc, andis also provided with a cam portion 105 which 150 is normally inengagement with the long cutout portion 99 of the associated disc. Thetooth 104 is formed with a gentle slope so that, if the clutch washer isrotated in one direction, it will carry the disc 97 with it in the samedirection, whereas if the clutch washer is rotated in the oppositedirection, the spring 103 will permit the clutch washer to move awayfrom the disc, so that the clutch washer may be rotated without rotatingthe disc. The disc 97 remaining stationary, the cam portion 105 ridesover the face of the disc, and holds the tooth 104 out of engagementwith the face of the disc. If, however, the shaft 83 is rotated in theopposite direction, the tooth 104 engages in the notch 98 and carriesthe disc with it.

Formed integral with the sleeve 96 is a cam disc 107, which is providedwith a recess into which thesector 108 extends. The sector is in meshwith a similar sector 109, which is secured to the rock shaft 89 whichcontrols the detent of the multiplier register. The sector 109 andconsequently the shaft 89 are normally held in detent engaging positionby the spring 112, bearing against the arm 113 secured to the sector109. The spring is guided on a pin 114, which is broken away in Figure13 to disclose the construction of the meshing sectors. Rotation of thecam disc 107, in a clockwise direction, will cause rotation of thesector 108 in a counter-clockwise direction, and rotation of the sector109 in a clockwise direction, thus rocking the shaft 89 to release thespring pressure on the detent 87, thereby permitting the balls 92 toengage the teeth 91 and reset the numeral wheels 82 of the multiplierregister to zero.

At the other end or the shaft 83, the shaft is provided with a similarcollar 95A, sleeve 96A, disc 97A, and clutch washer 102A, the tooth ontheclutch washer 102Abeing faced in the opposite direction on the clutchwasher 102, so that the clutch washer 102 is effective to release onegroup of detents, when the crank shaft 93 is rotated in one direction,and the clutch washer 102A is effective to release the detentsassociated with the other register, when the crank shaft 93 is rotatedin the opposite direction. In the present construction, rotation of thecrank shaft in a clockwise direction returns to zero the numeral wheelsof the multiplier or quotient register and rotation of the crank 93 in acounterclockwise direction, returns the numeral wheels of the productregister to zero. Formed integral with the sleeve 96A is a cam disc 116,which is provided on its periphery with a recess in which the lever 117extends, the lever 117 being secured to the shaft 88,. which carries thespring pressed balls 90 associated with the detents of the productregister, so that rotation of thedisc 116 frees the detents associatedwith the numeral wheels 81 of the product register and permits thespring pressed balls 92 associated with these numeral wheels, to rotatethe numeral wheels to zero. It is apparent from the above,

that rotation of the shaft 83, on which the numeral wheels are mounted,in one direction, will reset -to zero the numeral wheels of one registerwithout aifecting the numeral wheels of the other register and thatrotation of said shaft in the opposite direction will reset to zero thenumeral wheels of the other register without affecting the numeralwheels of the first register.

The actuators are normally held in full cycle position by centralizinglevers 121 and 122. Secured to each actuator, preferably adjacent theouter ends thereof, is a flat surfaced cam 123 and 124, the centralizinglever 121 cooperating with the cam 123 and the centralizing lever 122cooperating with the cam 124. Each centralizing lever is provided with arelatively heavy spring 125 and the centralizing levers serve toposition the actuators in full cycle position and to hold them in suchposition.

Means are provided for locking the depressed keys 17 in depressedposition, upon the initial -movement of the actuator from full cycleposition and, since the centralizing levers are moved synchronously withthe movement of the actuators from full cycle position, one of thecentralizing levers 122 is employed to actuate the key locking means.Referring to Figure 6, it will be seen that each latching slide 26 isprovided adjacent its forward end with a downwardly bent tooth 127.Seated in notches formed in the tongues 24 is a locking bar 128 which isnormally held in downward or inoperative position by the spring 129. Thelocking bar is provided with teeth 131 (Fig. 7) which straddle a tongue24, to prevent longitudinal shifting of the locking bar. At its endadjacent the post 132, to which the spring 129 is attached, the lockingbar is provided with an upturned ear carrying a projecting pin 133. Atits other end, the locking bar is provided with a spring 134, attachedto another tongue 24, for holding the locking bar in the notches in thetongue. Means are provided for engaging the pin 133, to pull itbackward, and thereby rock the locking bar in a clockwise direction,moving it into position behind the downwardly projecting teeth 127, sothat the latching slides 26 are locked against backward or key-releasingmovement. In the present construction, the locking bar is rocked by thecentralizing lever 122, upon movement of the actuator from full cycleposition.

Pivoted to the centralizing lever 122 is a bar 136 which is provided atits forward end with an upward projection 13?, which lies in front ofand adjacent to the pin 133, when the actuator is in full cycleposition. Therefore, when the machine is set to perform problems inmultiplication or division, upon the initial movement of the actuatorfrom full cycle position, the projection 137 moves backward, engagingthe pin 133 and rocking the locking bar 128 to move it into positionbehind the teeth 127. In order to prevent jamming or breaking of themachine, in the event that the slides 26 are not properly positionedwhen the locking bar 128 is rocked, the bar 136 is provided witharesilient extensible coupling 138, the spring forming part of thecoupling being of suflicient tension or compression to cause theoperation of the locking bar 128 under normal circumstances but, beingyieldable, to permit rotation of the actuator, in the event that one ormore of the latch slides 26 is not properly positioned.

When the machine is used in performing problems in addition, it is notdesired that the depressed keys be locked in depressed position, sinceit is desired that these keys be released immediately after the ordinalregistration action has occurred, and before the actuator reaches fullcycle position, to permit the rapid introduction of the next number tobe added. For this reason, means are provided for disabling the keylatch locking means when the machine is to be used for addition. Forthis purpose, the machine is providedwith an addition key 142 which isurged upward by the spring 143 and which is provided with a notch 144engageable with the cover plate 56 to hold the key in de= pressedposition. The stem of the key 142 is provided with a laterally extendingpin 145, which is disposed in a slot 146 in the bar 136. When the key142 is depressed, the bar 136 is rocked downward, moving the projection137 away from the pin 133, so that as the lever 136 oscillates, it doesnot contact with the pin 133 and consequently does not operate thelocking bar 128.

Means are also provided for simultaneously moving all of the keylatching slides 26, when it is desired to clear the keyboard. Pivoted ona shaft 147 disposed adjacent the front end of the machine, is a lever148, having a long vertical leg 149 which lies in front of all of theupturned lips of 33 on the ends of the slides 26. By rocking the lever148, all of the slides 26 are moved forward, releasing the depressedkeys. Two differ= ent means are provided for releasing the keys, onecomprising a clearance key which is hand operated, and the othercomprising mechanism which is actuated during the rotation of theactuator. Mounted in the machine adjacent its forward end is a clearancekey 152 which is pressed upward by a spring 153. The clearance key isprovided with a shoulder 154 which overlies the horizontal leg 155 ofthe lever 146, which arm 155 is normally held in raised position by thespring 156. Downwardpressure on the key 152 therefore rocks the lever148 to push the key latching slides 26 backward to release the depressed key.

When the machine is used for performing problems in addition, it isdesirable to clear -thev keyboard before the actuator returns to fullcycle position and means are provided which are actuated in time withthe actuator and which are set in operative position by the depressionof the addition key 142, for accomplishing. this purpose. Journalled ona pin'158 projecting'eccentrically from the gear 43, which'is secured tothe crank 42, is a rod 159 which is provided at its forward end with adown-turned car 161', which oscillates back and forth as the crank 42 isrotated. Intermediate its end, the bar 159 is mounted on a pin 162carried by the stem of the addition key 142. When the addition key is inelevated position, the pin 162 positions the ear 161 above the lever149, so-that as the bar 159 oscillates, it has no function with respectto the lever 1 49. When the addition key 142 is depressed, however, itmoves the projection 161 into position in front of the lever 149 so thatas the crank is rotated, the projection 161 contacts with and rocks thelever 149 to move the slides 26 to release the depre'ssed keys. Theselecting elements of the actuator. which are set by the keys are lockedin set position by mechanism to be hereafter described and-theoscillating bar 159 may operate to release the depressed keys at anytime after the selecting element lock has become. effective, preferablythe parts being constructed that the release of the keys occurs at abouthalf cycle. Each selecting element 7 which 5. As the actuator moves fromfull cycle position, the arm 168 rides up onto the high part of the cam,rocking the shaft 167 and moving the pawls 166 into engagement with theratchet 165, looking the selecting elements in position. The length ofthe low portion of the-cam is such that the selecting elements arelocked in position, except when the actuator is adjacent full cycleposition. This relatively long period of unlocking of the selectingelements is desirable when the machine is employed in sol'vingproblemsin addition, but in multiplication, it is desirable that the se1ectingelementsbe held in locked position at all times, except when theactuator is in full cycle position. Means are therefore provided foradjusting the locking members to accomplish this result.Projectingdownwardly from oneof the pawls 166 is an arm 171 (Figure 5)carrying a pin 172. Arranged adjacent the pin 172 is the upwardlyprojecting end 173 of the oscillating arm 174 which is fulcrumed on ashaft 175, secured eccentrically to the gear 44. The arm 174 is providedwith a pin 176', which rides on the presses the rear arm of the lever177, the rear arm being shown in its elevated position in Figure 5. Whenthe key 142 is in its elevated position, the lever 177, cooperating withthe pin 176, holds the oscillating arm 174 in position so that upon theinitial movement of the actuator from full cycle position, theprojection 173 engages the .pin 172 and rocks the pawls 166 to-move theminto locking engagement with the arcuate ratchet 165 in advance of thetime in which these pawls would .be moved by the arm 168. On the returnof the crank handle to full cycle position, the parts are returned tothe position shown in Figure 5, releasing the holding pawls. When theaddition key 142v is depressed, the rear end 177 of the lever isdepressed, permitting the oscillating arm 174 to fall, to move the pathof the projection 173 from theplane of the pin 172, so that theprojection 173 does not function with respect to the locking pawls 166.,This construction per mits the desired freedom and earlyrelease of theselecting elements, when the machine is usedfor performing problems inaddition, but retains the selecting elements in locked position,substantially continuously, when the machine is employed in solvingproblems in multiplication, which problems require a multiple rotationdf the crank shaft.

I claim:

1. In a calculating machine, two registers, each comprising a series ofnumeral wheels, a shaft on which the numeral wheels of both registersare rotatably mounted, means carried by the shaft for rotating thenumeral-wheels to zero, means associated with each register forrestraining the wheels from rotation during operation of the zeroresetting means and means operated by selective operation of the shaftfor releasing the selected restraining means.

2. In a calculating machine, two registers, each comprising a series ofnumeral wheels, a shaft on which the wheels of both registers arerotatably mounted and by which they are rotatable, means normallyholding the numeral wheels against rotation with the shaft and meansoperated by selective rotation of the shaft for releasing the selectedholding means.

3. In a calculating machine, two registers, each comprising a series ofnumeral wheels, a shaft on which the numeral wheels of both registersare rotatably mounted, means for independently moving the numeralwheels, detents for restraining the movement of the numeral wheelsduring rotation of the shaft, and means operated by selective rotationof the shaft for releasing the detents from the numeral wheels of oneregister and turning said released numeral wheels to zero.

4. In a calculating machine, two registers, each comprising a series ofnumeral wheels, a shaft on which the numeral wheels of both series arerotatably mounted, a series of spring pressed detents associated witheach series of numeral wheels, zero resetting means associated with saidshaft, means operated by rotation of the shaft in one direction forreleasing one series of spring pressed detents and means operated by therotation of the shaft in the opposite direction for releasing the otherseries of spring pressed detents.

5. In a calculating machine, two registers, each comprising a series ofnumeral wheels, a shaft on which the numeral wheels of both series arerotatably mounted, a series of spring pressed detents associated witheach series of numeral wheels, zero resetting means associated with saidshaft, means for releasing the detents associated with one register,means for releasing the detents associated with the other register,means actuated by rotation of the shaft in one direction for operatingone detent releasing means and means operated by rotation of the shaftin the opposite direction for operating the other detent releasingmeans.

6. Means for holding the numeral wheels of either of two registersagainst zero resetting rotation during the zero resetting rotation ofthe numeral wheels of the other register, comprising the combination ofa shaft on which all of said wheels are mounted, means carried by theshaft tending to rotate said numeral wheels, means engaging the saidnumeral wheels to prevent rotation thereof by the means carried by theshafts and means operated by selective rotation of the shaft forreleasing the rotation preventing means associated with the numeralwheels of the selected register.

7. In a calculating machine, two registers, each comprising a series ofnumeral wheels, a shaft on which the numeral wheels of both series arerotatably mounted, means normally holding the shaft in zero position,means carried by the shaft for moving the numeral wheels to zeroposition, detents normally restraining the numeral wheels againstrotation with the shaft, means ,operated by movement of the shaft in onedirection from zero position for releasing the detents of one registerand meansoperated by movement of the shaft in the opposite directionfrom zero position for releasing the detents of the other register.

8. In a calculating machine a series of registering wheels, a rotatableshaft on which said wheels are rotatably mounted, means carried by theshaft for rotating the wheels to zero, means 1 associated with saidwheels for preventing rotation thereof with said shaft and meansoperable by said shaft for disabling the preventing means associatedwith fewer than all of said wheels, whereby the registration on certainwheels is retained during resetting of the remainder.

9. In a calculating machine, a series of coaxially mounted registeringwheels, means for releasably driving said wheels to zero, meansassociated with said wheels for preventing driving thereof by saidmeans, and means for disabling said preventing means associated withfewer than all of said wheels, whereby the registration on certain ofsaid wheels is retained during resetting of the remainder.

10. In a calculating machine, two registers, each comprising a series ofnumeral wheels, mechanism supporting said numeral wheels for rotation, aseries of spring pressed detents associated cooperatively with each ofsaid series of numeral wheels, zero resetting means associated with saidsupporting mechanism, and means, operated upon rotation in one directionof the supporting mechanism for releasing the series of spring presseddetents associated therewith, and means operated upon rotation in theother direction of the supporting mechanism for releasing the otherseries of spring pressed detents.

11. In a calculating machine, two registers, each comprising'a series ofnumeral wheels, mechanism for supporting said numeral wheels forrotation, means for independently moving the numeral wheels in each ofsaid registers, detents for restraining the movements of the numeralwheels during rotation of the supporting mech- Y

